BASHUR, Iraq (CNN) --In the first move to secure northern Iraq for ground troops, about 1,000 paratroopers dropped into Kurdish-controlled territory under cover of darkness early Thursday to secure an airfield for coalition use, U.S. officials said.

The soldiers from the U.S. Army's 173rd Airborne Brigade parachuted to the ground, then walked across flat, open fields and assembled in the new morning light. They then began to secure the Harir airfield, not far from Bashur.

Harir is about 40 miles from the border of Iraqi-controlled territory and is within an area not hostile to coalition forces.

The paratroopers stepped out of C-17 Globemaster transport planes that took off from an undisclosed airfield in Europe, according to CNN Correspondent Steve Nettleton, who is embedded with the unit there.

The cargo planes returned to the airfield empty, and the Army will now begin to load military equipment -- including tanks, Bradley fighting vehicles, and armored personnel carriers -- onto the planes to bring them into northern Iraq, Nettleton said.

The Army aims to secure the northern area so a larger armored force can enter. Another goal is to stabilize the area to prevent other forces from coming in, whether it be Turks from the north or Iraqis from the south. The move will also eventually lead the way to the entry of humanitarian aid.

The U.S. military had hoped to transport vehicles and troops over land, but failed to reach an agreement with Turkey about using its military bases to gain access to northern Iraq.

Two U.S. helicopters at the Harir airfield also unloaded personnel and equipment. Kurdish forces met them and transported them in three-ton trucks.

The 2,000-strong 173rd Airborne Brigade is based in Vicenza, Italy, and the 1st Battalion, 63rd Armor, which is bringing in its armored vehicles, is based in Bilsek, Germany.

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